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From: dbw@cup.portal.com (Dale B Walker)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Circular Referencing Think C Classes
Message-ID: <33634@cup.portal.com>
Date: 7 Sep 90 21:13:53 GMT
References: <BRIANJ.90Sep5175658@witsend.cs.umd.edu>
Distribution: na
Organization: The Portal System (TM)
Lines: 53



You Write:

>What do I need to do in order to let two classes "talk" to each other.
>It took me awhile to figure out that this was my problem.  Is there
>some sort of forward declaration for classes (class structs)
>referenced in this way.

In your examples  you have two .h files that include each other.  
I encountered the same problem.
  
My solution was to have only one of the files include the other - 
and in the case of the second file, use the superclass of the desired 
class and cast it as necessary in the c code defining the methods.  

	Dale

Example:

/* Class1.h */

#define _H_Class1
#include <CObject.h>

struct Class1 : indirect {
	CObject		*three;
	
	void 		doit (void);
};
-------------------------------
/* Class3.h */

#define _H_Class3
#include <CObject.h>
#include "Class1.h"

struct Class3 : CObject {
	Class1		*one;
	
	void 		doit (void);
};
--------------------------------
/* Class1.c */

#include "Class1.h"
#include "Class3.h"

void
Class1::doit()
{
	((Class3 *) three)->doit();
}